Image Files
Bitrot resistance of next-generation image formats
Bitrot happens. So, what happens when I flip one random bit in AVIF and JPEG XL images. Improved data packing means less redundancy and more corruption.
Compression
Compression
Does the web still need HTTP Deflate?
The compression format war of the last decade was won by Gzip. Why do web browsers still support the legacy HTTP Deflate (Zlib) format? It’s time to deprecate it.
Image Files
Comparing file sizes of lossless WebP vs FLIF vs PNG
The FLIF lossless image format makes big claims on file size savings, but lossless WebP actually delivers smaller lossless image files.
HTML
Optimize your <head> metadata for better compression
Reduce the file size of compressed webpages by optimizing the order of <meta> and <link> elements in the document <head> section.
Compression
Compressed favicons are 70% smaller but 75% are served uncompressed
The majority of websites don’t compress their favicon files despite an impressive average file size reduction of over 70 %.
Apache HTTPD
Don’t rely on mod_negotiation to serve pre-compressed resources
Apache’s module for server-driven HTTP content negotiation isn’t suited to make decisions about which pre-compressed resource to serve.
Compression
WebP image file sizes compared to equivalent Guetzli and Zopfli
Modern and backwards-compatible lossless compression methods reduces the file size-gap between the newer WebP image format, and legacy formats like JPEG and PNG.
Compression
WordPress with PHP GD’s image resize artifact-pattern problem
PHP GD graphics library (libgd) causes bad artifact-patterns when downsizing images. Makes images bigger and quality lower.
Compression
New Save-Data HTTP header tells websites to reduce their data usage
The new HTTP Save-Data request header can help websites determine the bandwidth constraints of their visitors. Plus, a browser extension for users to adopt it.
Apache HTTPD
New Brotli compression filter module now in Apache Web Server
Learn how to enable the new Brotli compression module alongside Gzip compression in the Apache HTTPD server.
Compression
MacOS adds XZ-compression support
Apple adds command-line support for the high-efficiency XZ file compression format in MacOS 10.10 “Yosemite.”